#include<bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int visited[100001];
void dfs(int nod){
if(visited[nod]==1)return;
visited[nod]=1;
for(int next:graf[nod])dfs(next);
return;}
int main(){
int nr_noduri,nr_muchii;
fin>>nr_noduri>>nr_muchii;
vector<vector<int>> graf(nr_noduri+1);
for(int i=1;i<=nr_noduri;i++){
int n1,n2;
fin>>n1>>n2;
graf[n1].push_back(n2);
graf[n2].push_back(n1);}
int rez=0;
for(int i=1;i<=nr_noduri;i++){
if(visited[i]==0)rez++,dfs(i);}
fout<<rez;
return 0;}